Solder powder size is a popular topic in the electronics industry due to the continuing trend of miniaturization of electronics. The question commonly asked is “when should we switch from Type 3 to a smaller solder powder?” Solder powder size is usually chosen based on the printing requirements for the solder paste. It is common practice to use IPC Type 4 or 5 solder powders for stencil designs that include area ratios below the recommended IPC limit of 0.66. The effects of solder powder size on printability of solder paste have been well documented.
The size of the solder powder affects the performance of the solder paste in other ways. Shelf life, stencil life, reflow performance, voiding behavior, and reactivity / stability are all affected by solder powder size. It is well understood that one cannot use every solder powder size with a particular solder paste. The solder paste must be formulated to work properly with the desired solder powder size. Here are recommendations for optimal use of each solder paste and solder powder size based on performance in this work.
Solder paste manufacturers are looking ahead to the future needs of the electronics industry. Smaller solder powder sizes are becoming increasingly common for miniaturized electronic applications. Solder paste manufacturers are formulating products for use with the smaller solder powder sizes in order to address these needs.
